1. Field of the Invention
The invention relates to inflatable articles and, more particularly, to a method and apparatus for manufacturing globular inflatable articles such as balloons in far greater quantities than heretofore has been possible.
2. Description of the Prior Art
A popular technique for the manufacture of inflatable articles such as balloons, beach balls and so forth consists of dipping a number of suitably configured forms into a bath of molten latex. Typically, a number of forms are suspended from the underside of a carrier. The forms are cleaned, coated with a coagulant and/or stripping agent such as talc or soapstone, dipped into a bath of molten latex, removed from the latex after a desired thickness of latex has been deposited upon the forms, dried at least partially after removal from the latex bath, and stripped of solidified or semi-solidified latex. All of these techniques are well known in the art and do not form a part of the present invention per se.
In those cases where globular articles such as round balloons are being produced, the forms used heretofore have been provided in a variety of configurations. The simplest configuration has been that of a cylindrical stem having a spherical or semi-spherical end portion. The inflated object produced by such a form obviously conforms substantially to the exterior configuration of the form. Other forms suitable for producing globular inflated articles are known. For example, forms having flutes or globular forms having depresssions have been used. In a typical fluted form, an equal number of flutes extend radially from the longitudinal centerline of the form. The flutes are radially spaced from each other the same extent. Although the distance from the centerline to the outermost portion of the flutes may vary along the length of the stem, all of the flutes at a given axial station project outwardly from the centerline the same or nearly the same distance. Stated differently, at any plane taken through the form at right angles to the longitudinal centerline of the form, the flutes project outwardly in a radial pattern and the outermost portion of the flutes defines a circle. By this configuration, the surface area of a given form is greatly increased compared with a smooth surfaced spherical or semi-spherical form, and a large inflated article can be produced through the use of a form having relatively small exterior dimensions.
In those globular forms employing depressions rather than flutes, a number of identically shaped depressions are located equidistantly circumferentially of the form and are located at the same axial location relative to the centerline. A plane taken at any axial location perpendicular to the centerline will show (a) the depressions arranged equidistantly of the centerline, (b) the depressions shaped the same, and (c) the outermost portion of the form defining a circle or an ellipse. By suitably shaping the depressions, relatively large inflated articles of spherical or semi-spherical configuration can be produced.
Although conventional forms function well to produce inflated articles of desired shapes, a problem exists with respect to the quantity of articles which can be produced through the use of these known forms. Because the radially outermost portion of each form at any selected axial location defines a circle or an ellipse, the form-to-form spacing among a number of forms suspended from the underside of a carrier is limited by the greatest diameter of the forms. That is, the centerlines of spherical forms cannot be located any closer to each other than the greatest diameter of a given form and the centerlines of semi-spherical forms cannot be located any closer to each other, at least in adjacent rows, than the greatest diametric dimension of a given form. This has rather severely limited production capabilities in that a considerable amount of "wasted" space remains among adjacent forms secured to a carrier.